Comparative Efficacy of Different Fungicides against Late
Blight Diseases of Potato incited by Phytophthora
infestans (Mont.) de Bary and its Management

*1Siddique
N. A and 2Swapon N. H

1Scientific
Manager, Ejab Agro ltd. Thakurgaon, Bangladesh

2 Chief Operation Officer, Ejab Agro ltd. Thakurgaon,
Bangladesh

*corresponding author E-mail: siddiqueibsc@yahoo.com

Accepted 1 July
2016

Abstract

Efforts made in present
investigation to evaluate the concentration of a few
commonly used fungicides for their comparative efficacy
against Phytophthora infestans (Mont.) de Bary- the
incited of late blight, with a view to select the most
effective fungicides for the disease management. Six
fungicides were selected among these, Sunoxanil 72 WP (Cymoxanil
8% + Mancozeb) showed the best result to prevent the late
blight before appearance of the disease (Prophylactic
measures) and Sunoxanil 72 WP (Cymoxanil 8% + Mancozeb) was
combined with Contaf 5EC (Hexaconazol 5%) showed the most
effective role to prevent the late blight after appearance
of disease (Curative measures). The highest 99.70% of
disease control and the highest yield (26.68 ton/ha) were
recorded on fungicides containing 3.5mg/L Sunoxanil 72 WP (Cymoxanil
8% + Mancozeb 64%) with 3.0ml/L Contaf 5EC (Hexaconazol 5%)
during 2015-2016. It was concluded that Sunoxanil 72 WP (Cymoxanil
8%+ Mancozeb 64%) acted as the best fungicide when applied
as prophylactic measures. Sunoxanil 72 WP (Cymoxanil 8%+
Mancozeb 64%) was combined with Contaf 5EC (Hexaconazol 5%)
showed the best result when applied as curative measures.
The lowest 75.68 % of disease control and the lowest yield
(15.67 ton/ha) were recorded on fungicides containing 2.0
mg/L Ridomil MZ 72 (Metalaxyl 8%+Mancozeb 64%) with 1.0 ml/L
Autostin 50 WDG (Carbondaxim 50%) during 2014-2015. On the
other hands when Actiphose was used with Mancozeb (Indrofil
M-45) showed comparatively better performance. Plant growth
was gradually prohibited for application of Carbondaxim
along with the yield was gradually decreased.